# -*- coding: utf-8 -*-
# @Time    : 2021/4/18 11:49
# @Author  : Chen
# @Email   : 2356458272@qq.com
# @File    : 判断正整数.py
# @Software: PyCharm
while 1:
    a = input("请输入：")
    try:
        a = int(a)
        if a >0:
            print(a)
            break
    except ValueError:
        pass